I recently purchased someone else's project, the engine was modified and the seller told me I would need a adjustable map sensor. I understand what it does but do not know where to purchase one and am a little confused on how to install. Any help would be appreciated

Somebody used to sell one. RockIt? Can't remember, it's been a while. You could also do an SAFC install. It's basically a super duper MAP adjuster. I just took mine out (hopefully getting tuned soon) and will be putting it up for sale when It around to it.

A little late to the party here but its a little concerning that you would add something after being told by a PO that you needed to do so. Do you understand why you need to? Is there a specific issue you need to combat?

Its important to understand the why before you go out and do something. typically an adjustable MAP isn't something you just throw at a problem and pray it fixes it.

If it feels right, then STROKE it!

You're lucky that hundred shot of CAPS LOCK didn't blow the welds on the forum!!

I had contacted the guy that makes them on Leigh performance. they were about $35 posted on the site. he told me he wasn't sure when he'd be making another batch of them so he couldn't give me an estimated time of when they'd be available. I came back and told him I'd PayPal him $60 to make me a one off, kind of like an offer he couldn't refuse. had it in the mailbox in a week.

very nice guy and works very well.

I tried making one myself a little over a year ago using the instructions on angel fire (I think I'm not sure) and grounded out the 5V from my computer and fried it. ($600 later) id rather pay someone to make one I know works rather than grenade my ECU again

Muad'Dib wrote:A little late to the party here but its a little concerning that you would add something after being told by a PO that you needed to do so. Do you understand why you need to? Is there a specific issue you need to combat?

Its important to understand the why before you go out and do something. typically an adjustable MAP isn't something you just throw at a problem and pray it fixes it.

I agree. the computer uses a factory programmed fueling table to keep the air fuel ratio as close to 14.7 (claimed as "perfect") as possible, until ~70% Throttle. Then it uses readings from the Manifold air pressure sensor (MAP) and adjusts the injector bursts accordingly. the MAP sensor works by taking the 5V reference from the computer, modifying that voltage by (x)% depending on the reading from the sensor, and sends it back to the computer. by changing the input voltage to the sensor, it will still modify it by (X)% but has a different number to start with. Higher voltage going in (5.2-5.5) Will richen the mixture, lower voltage (4.9-4.7) will lean out the mixture.

so knowing how this adjustor works you now need to know what the PO is trying to bandaid by throwing an adjustment at the motor. if it's a lean condition it could mean you have clogging injectors, or failing o2 sensors (upstream which monitors the AFR).

also it is dangerous to modify the AFR without a Wideband o2 to monitor the radio. if you go too lean you'll fry your pistons and cook your head. if you go too rich you'll wash your cylinders and lose a lot of power, and possibly clog your cats (if they still exist). the MAP adjustor probably* won't modify it outside safe AFR towards the lean side, but it should still be monitored and adjusted in very tiny increments.